The present invention relates to a diaphragm pump, particularly for supplying fuel to an internal combustion engine.
Pumps of this type comprise a lower body and an upper body with mating annular peripheral flanges between which the periphery of the diaphragm is gripped. The lower body contains a mechanism for deforming the diaphragm in a reciprocating manner. The upper body internally contains two housings. The two housings contain respectively an automatic intake valve and an automatic delivery valve through which a chamber overlying the diaphragm is put into communication with an intake pipe union and a delivery pipe union respectively. The intake and delivery pipe unions branch from corresponding spaces overlying the respective valves.
In some known pumps of a first type, the intake and delivery pipe unions are carried by the upper body of the pump in fixed orientations and positions.
In other known pumps of a second type, the two pipe unions are carried, also in fixed orientations and positions, by a lid formed from sheet metal which covers and surrounds the upper body. The lid has a lower edge that keeps the flanges of the two bodies together by seaming, as well as retaining the lid in position.
Because of the fixed orientations and positions of the pipe unions in both these types of pump, it is not possible, for example, in the case of motor vehicles, to use standarized pumps which are suited to the requirements of various models of motor vehicles, these requirements being created by the differences of positioning and orientation of the fuel intake and delivery pipes which exist between one vehicle model and another.
In pumps of the second type, there are also sealing problems between the delivery and intake zones defined by the upper body and the lid.
The manufacturers of diaphragm pumps are forced to design upper bodies or lids of several different types, with pipe unions arranged in different ways.
Thus, repairers are also forced to choose from several types of diaphragm pumps to find one which has the specific pipe union arrangement corresponding to the positions and orientations of the piping with which the unions are to be connected. Hence, it would be desirable to provide a so-called universal diaphragm pump, that is, one in which the position and orientation of the pipe unions would be adaptable to different requirements.
One object of the invention is to provide a pump which satisfies this desire while not having the sealing problems of the second type of known pump.